/*
 * Copyright [2013-2021], Alibaba Group Holding Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.alibaba.polardbx.executor.mpp.operator.factory;

import com.alibaba.polardbx.executor.operator.ConsumerExecutor;
import com.alibaba.polardbx.executor.operator.Executor;
import com.alibaba.polardbx.optimizer.context.ExecutionContext;

import java.util.ArrayList;
import java.util.List;

public class LocalBufferConsumerFactory implements ConsumeExecutorFactory {

    private ExecutorFactory parentExecutorFactory;
    private List<ConsumerExecutor> consumerExecutors = new ArrayList<>();

    public LocalBufferConsumerFactory(ExecutorFactory parentExecutorFactory) {
        this.parentExecutorFactory = parentExecutorFactory;
    }

    @Override
    public ConsumerExecutor createExecutor(ExecutionContext context, int index) {
        synchronized (this) {
            if (consumerExecutors.isEmpty()) {
                List<Executor> executors = parentExecutorFactory.getAllExecutors(context);
                for (Executor executor : executors) {
                    consumerExecutors.add((ConsumerExecutor) executor);
                }
            }
        }
        return consumerExecutors.get(index);
    }
}
